Report on Manam (Papua New Guinea) — June 1991
Bulletin of the Global Volcanism Network, vol. 16, no. 6 (June 1991)
Managing Editor: Lindsay McClelland.
Manam (Papua New Guinea) Occasional ash emissions
Please cite this report as:
Global Volcanism Program, 1991. Report on Manam (Papua New Guinea). In: McClelland, L. (ed.), Bulletin of the Global Volcanism Network, 16:6. Smithsonian Institution. https://doi.org/10.5479/si.GVP.BGVN199106-251020.
Papua New Guinea
4.08°S, 145.037°E; summit elev. 1807 m
All times are local (unless otherwise noted)
"Both craters released weak emissions of white vapour. However, some greyish, ash-laden clouds were also occasionally emitted. Between 5 and 9 June, deep roaring sounds were heard from Southern Crater and plumes of ash occasionally rose to 150-700 m above the crater rims. Similar activity recurred between 25 and 29 June. Although no night glow was observed, the seismicity was at a moderately high level and radial tilt measurements fluctuated by 3 µrad."
Geologic Background. The 10-km-wide island of Manam, lying 13 km off the northern coast of mainland Papua New Guinea, is one of the country's most active volcanoes. Four large radial valleys extend from the unvegetated summit of the conical 1807-m-high basaltic-andesitic stratovolcano to its lower flanks. These "avalanche valleys" channel lava flows and pyroclastic avalanches that have sometimes reached the coast. Five small satellitic centers are located near the island's shoreline on the northern, southern, and western sides. Two summit craters are present; both are active, although most historical eruptions have originated from the southern crater, concentrating eruptive products during much of the past century into the SE valley. Frequent historical eruptions, typically of mild-to-moderate scale, have been recorded since 1616. Occasional larger eruptions have produced pyroclastic flows and lava flows that reached flat-lying coastal areas and entered the sea, sometimes impacting populated areas.
Information Contacts: P. de Saint-Ours, RVO.